The rapid and continued identification of gene mutations that predisposes people to cancer has led to a better understanding of inherited susceptibility to cancer (ISC). ISC is a high-risk condition for cancer. No studies of risk perception in people with ISC have been published in the nursing literature. No qualitative studies of risk perception in ISC are found in the literature. This proposed research will, therefore, significantly contribute to the overall knowledge base of perceived risk of cancer in adults with ISC. Knowledge of risk perception is important in understanding the decisions people with ISC make concerning genetic testing and strategies for cancer prevention and detection. Once nurses better understand how people with ISC perceive their cancer risk, other critical studies, such as interventions targeting genetic counseling and decision making for genetic testing or studies of nursing care guided by genetic markers of cancer risk, can logically follow. The purpose of this study is to gain understanding of risk perception in ISC. Specific aims are to (1) conduct phenomenology research to identify the essential structure of risk perception in adults with ISC by identifying categories of data and coding data themes for theory building and instrument development; (2) develop a theory-driven preliminary model of perceived risk of cancer in adults with ISC; and (3) develop and test an instrument on the preliminary model to measure risk perception in adults with ISC who are eligible for genetic testing. Qualitative and quantitative approaches will be used for research design and analysis: phenomenology, preliminary model/theory development, and instrumentation.